The present invention relates to an ejection mechanism to remove hauled material from a hauling body and, more particularly, to such a mechanism which is actuated in multiple steps.
Articulated trucks are commonly used in industry to haul material from one location and spread it in another location. Articulated trucks dump the hauled material either by tilting the body of the truck or by ejecting the material with a mechanized pusher/ejector blade. Ejector trucks are useful in many applications where a traditional tilting dump truck is undesirable or impractical. For instance, if there are power lines or a low bridge or other structure located above the worksite, the ejector truck can dump its load without contacting the overhead obstruction as would a tilting dump truck. Also, an ejector truck can spread the dumped material more easily and accurately than can a gravity-powered tilting dump truck, since the powered ejector blade gives the operator a great deal of control over the flow rate of the material.
Ejecting the hauled material from the truck is currently accomplished using a multi-part telescoping hydraulic cylinder to push an ejector blade from the front of the body to the rear of the body in a known manner. These designs have worked well, but could be improved. The telescoping hydraulic cylinder is very expensive to manufacture, operate, and maintain. It requires a large amount of hydraulic fluid to fully extend, with all of the accompanying fluid supply and routing issues. The dimensions of, and clearances between, the telescoping sections must be very precise, and there are multiple sections needed to extend the cylinder to empty the truck totally, with each of those sections requiring meticulous machining and assembly. The cylinder will not function as desired if dirt, debris, or other hauled material spills over the ejector blade and scratches or dents the telescoping sections. Also, the extreme length of the extended telescoping cylinder makes it more likely to sag in the unsupported midsection. Over time, such sagging could bend the sections slightly, thus ruining the precise alignment of the sections.
The present invention is directed to overcoming one or more of these complications by providing a method and apparatus of a multi-actuator ejection mechanism which: is protected from spillover material; uses common, simple components; includes intermediate support for the linear actuators; and is economical to manufacture and use.
In an embodiment of the present invention, a multi-actuator ejection mechanism is provided. The multi-actuator ejection mechanism includes an anchor member, an ejection carriage, an ejector blade, a first linear actuator, and a second linear actuator. The ejector blade is located a predetermined distance from the anchor member and is adapted to move longitudinally with respect to the anchor member. The first linear actuator has a first end secured to the anchor member and a second end secured to the ejection carriage, and is adapted to move the ejection carriage longitudinally with respect to the anchor member. The second linear actuator has a first end secured to the ejection carriage and a second end secured to the ejector blade, and is adapted to move the ejector blade with respect to the ejection carriage.
In an embodiment of the present invention, a method for providing a multi-actuator ejection mechanism to an ejector body is provided. The method includes the steps of extending a first linear actuator, moving an ejector carriage from a first carriage position to a second carriage position, moving an ejector blade from a first blade position to a second blade position, extending a second linear actuator, and moving the ejector blade from the second blade position to a third blade position.
In an embodiment of the present invention, a multi-actuator ejector trailer is provided. The multi-actuator ejector trailer includes a trailer body, a ground-engaging device attached to trailer body and adapted to provide motive means to the trailer body, and an ejector mechanism attached to a forward portion of the trailer body. The ejector mechanism includes an ejector blade, an anchor member, an ejector carriage, a first linear actuator, and a second linear actuator. The ejector blade is located on top of the trailer body and is adapted to move from the forward portion of the trailer body to a rearward portion of the trailer body. The anchor member is located forward of the ejector blade and is substantially fixed in position. The ejector carriage is located between the ejector blade and the anchor member and adapted to move from a forward position near the anchor member to a rearward position near the ejector blade. The first linear actuator is located between the anchor member and the ejector carriage, attached to the anchor member and the ejector carriage, and operative to move the ejector carriage with respect to the anchor member. The second linear actuator is located between the ejector carriage and the ejector blade, attached to the ejector carriage and the ejector blade, and operative to move the ejector blade with respect to the ejector carriage.